Appendix VI. ri 55 out that six times the power could be obtained by using the gas directly in suitably built engines, and then proceeded to carry his suggestions into effect by means of a 20 H.P. gas engine at Motherwell, when one electrical H.P. per Ib. of coal was effected, as much as can be obtained only in the very best steam engines. In this case, however, the smelting was done in addition. Further, there was less difficulty in burning in a cylinder than The Monti C-ALS Plant. under a steam boiler on account of the nature of the gas. The gas leaves the blast furnace with a fair proportion of CO, according to the reaction on p. 74, only a little CO2 being present; in fact, an ideal producer gas. The chief trouble has been the presence of fine dust (5 %) and moisture, and these must be eliminated by suitable filtration and washing, or failure is inevitable. The composition of the gas varies according to the plant, but may be averaged as follows :— CO CH4 H CO, N ro 7*o 59*o diluents. TQO'O parts by volume.